hi
On the AT&T Network, to unlock the LG Shine or CU720, it’s pretty simple:

Put a AT&T or Cingular SIM in the phone; it does not have to be an active SIM

Enter *#865625# then the 16 digit unlock code*

Device should say: Network Lock Deactivated

Phone may automatically reboot

*The 16 digit code can be obtained by calling AT&T Technical Support and given the representative the IMEI number. In exchange they will give you the Subsidy Unlock Code.To obtain the IMEI number, type *#06# on your device. This 16 digit number is not the same as the unlock code, this is the IMEI number to give to AT&T Technical Support in exchange for the 16 digit Subsidy Unlock Code.

You can trace a phone with an IMEI code in India as there is a very active cyber cell which is functioning. You need to just lodge your complaint at the nearest police station with the proof of your purchase with the IMEI number. There after the matter willbe taken up to check if anyone is using the same phone as the IMEI number can be traced from all the service providers. But what you must decide is to judge whether the phone in question is an expensive one and worth it to go after as this might involve some trips to the staiton with all possiblilites of delays. So unless your phone is very dear/ expensive you must decide on your action. Hope I could help. Good day

Not to worry. Your cell phone operator or the police can help you find it if only you can give them the IMEI number.

If you don't have your phone's IMEI number, it is impossible to track the phone since your phone doesn't have the inbuilt tracker software like samsung phones...

The IMEI (international mobile equipment identity) is your handset's fingerprint that helps track down your lost phone.Here's how you can find the IMEI number of your cell phone: Just punch in *#06#, and the phone will display a 15-digit number. Note this number.The IMEI number gets logged on to the SIM card and a cellular operator can locate the area from where a call is made

Your phone will ask for PUK code when you entered the PIN
code wrongly several times depending upon the mobile make. The mobile asks for
PUK code so that unauthorized persons do not use your mobile for wrong cause.

To get PUK code please contact your service provider
through phone or go directly to their office. They will provide you the PUK
code for your mobile. The PUK code is unique for each mobile phone model.so
that you can open your phone. When you planning to call your service provider
you cannot use your mobile as it is fully locked. Please use some other mobile
with same network to call your service provider.

This PUK
code prevents thieves from being able to
make use of stolen handsets, that is why it can only be given by the service
provider only.

While you get the PUK code ,the service provider
customer care officer will ask for your personal details to check whether the
mobile belongs to you only. If they are satisfied with your answers they will
provide with the PUK code

try to save your music and video files in your memory card. maybe some of it are saved in your phone memory. try to move those into your memory card. or if your had acquired your music/video via bluetooth, try to save that into your memory card and DELETE them out of your inbox. that will solve your problem.

Your provider can unlock the phone for you, after you finished the contract. Not every provider will do that without pointing out what is in the contract.
There are also sites, that can send you an unlock code, but before they send it, you have to pay a fee. Just try your provider, if that does not work, Google with the same words you used here, to find a less legal site, (Again it will cost you something)